1. Field of the Invention
The present invention relates to a character display apparatus and to a character input apparatus. The present invention is applicable to an apparatus having a display unit in which each of the number of lines and a number of characters in each line is limited to a small value, such as a tape printing apparatus and a seal making apparatus.
2. Discussion of the Related Art
In a tape printing apparatus, inputted characters (the term xe2x80x9ccharacterxe2x80x9d includes letter, symbol, pictograph, pattern, and the like throughout the specification and the appended claims) are printed on a tape in the form of a string (hereinafter a string of characters will be referred to as xe2x80x9ccharacter stringxe2x80x9d, an inputted character as xe2x80x9cinput characterxe2x80x9d, and inputted character string as xe2x80x9cinput character stringxe2x80x9d) , and the tape carrying such a printed character string is discharged and then cut into several portions. Each of the portions of the tape thus obtained is called xe2x80x9clabelxe2x80x9d.
Unlike in an ordinary word processor, in such a tape printing apparatus, since the printed resultant is a label and printing is performed on a tape in which limitation is imposed on the dimension in the transversal direction, the number of printed lines is limited by the apparatus itself. Further, in such a tape printing apparatus, since the number of characters in each line depends on cases, it is not realistic to constitute a display unit capable of displaying all the characters of a possible maximum allowable number at one time with respect to each line.
In view of the foregoing, in a tape printing apparatus, as a display unit for displaying input character string, a small-size display unit (e.g., a small-size liquid crystal display) which is adapted to display a small number of lines and a small number of characters in each line has been employed. In such a conventional small-size display unit, it is common that the number of display lines is determined to a value smaller than the maximum printable line number (e.g., four lines and eight lines) within the maximum tape width and that the number of characters in each line is determined to a value around five (e.g., six).
Accordingly, in the conventional display unit, in some cases, the number of input character string becomes larger than that of the number of lines which the display apparatus can display. In such cases, it is necessary to indicate which lines of the input character string is currently displayed. In the conventional apparatus, such indication is conducted by the following manner.
FIG. 2 shows a display surface 1 of a display unit in a tape printing apparatus in which print allowable maximum line number (the term xe2x80x9cprint allowable maximum line numberxe2x80x9d as used herein means the maximum number of lines which can be printed) is four, and the display allowable line number is one. As shown in FIG. 2, the display surface 1 has a character display area 2 which is adapted to display an input character string, and line number indicators 3-1 to 3-4 disposed at the left side portion of the display surface 1 along the top-to-bottom direction.
Each of the indicators 3-1 to 3-4 carries thereon a numeral representing a line number in the input character string, and shows an input state and/or a display state of each line constituting the character string by assuming a blinking display state, a light-on display state, or a light-off display state.
More particularly, when an indicator assumes the blinking state (hereinafter, an indicator assuming a blinking state will be often referred to as xe2x80x9ca blinking indicatorxe2x80x9d), the blinking indicator indicates that the line of the line number denoted by the numeral applied on the blinking indicator is currently displayed in the character display area 2. If the character display area 2 is of the type that two or more lines are displayed, only an indicator carrying the numeral indicative of the line number of the line at which the cursor stays among the display lines assumes a blinking state.
When an indicator assumes the light-on display state (hereinafter, an indicator assuming a light-on display state will be often referred to as xe2x80x9clight-on indicatorxe2x80x9d), the light-on indicator indicates that the line of the line number denoted by the numeral applied on the light-on indicator exists in the input character string. It should be noted that, among the lines existing in the input character string, the cursor attached display line is denoted by a blinking indicator as described above, and therefore the cursor attached display line is excluded from the object to be displayed in the lighting-on display state. This implies that, when the character display area is of the type that two or more lines are displayed, only the line (or lines) which is (or are) not attached with the cursor is (or are) indicated by a light-on indicator. It should be noted that the line indicated by the light-on indicator includes not only a substantial line but also a null line, both of which will be defined later.
When an indicator assumes the light-off display state (hereinafter, an indicator assuming a light-off display state will be often referred to as xe2x80x9clight-off indicatorxe2x80x9d), the light-off indicator indicates that the line indicated by the light-off indicator does not exist in the input character string. That is, the line indicated by the light-off indicator is neither the substantial line nor the null line.
The character display area 2 is an area for displaying characters. As the display method for the character display area 2, the dot display method (which is often called as xe2x80x9cdot representationxe2x80x9d or xe2x80x9cmatrix methodxe2x80x9d) is employed in which a character is displayed by turning on or off each of the dot segments arranged vertically and laterally. In contrast, each of the line number indicators 3-1 to 3-4 is adapted to display a specific fixed numeral, and is constituted by approximately one or two segments each of which is turned on or off so as to display a predetermined fixed number. As is known from the above description, the indicator of this type is different in constitution and function from a general numeral displaying indicator which is constituted by seven segments arranged in the shape of a numeral xe2x80x9c8xe2x80x9d.
In FIG. 2, the outline character xe2x80x9c1xe2x80x9d displayed in the character display area 2 is a line head mark 2M representing that the character displayed subsequent to the line head mark 2M is the head of the display line. The line head mark 2M is not displayed when the forefront character (in the case of the present embodiment, the leftmost character in the display area) of the displayed characters is not the forefront character of the display line. For example, assuming that the allowable display character number is five and the number of the input characters is seven, if the five characters displayed in the character display area are the second to sixth characters, the line head mark 2M is not displayed because the forefront character displayed in the character display area is not the forefront character of the display line.
As described above, in the conventional tape printing apparatus, since the line number indicator is provided, the user can know, even when the number of lines of the input character is larger than the display allowable line number, which line is present or absent and which line is currently inputted.
Meanwhile, if the tape printing apparatus is so constituted as to be capable of providing information which cannot be read from the displayed manner of the characters of the input character string as much as possible, the usability of the character printing apparatus is enhanced.
For example, there is an attribute indicative of whether the line is a substantial line or a null line. The term xe2x80x9csubstantial linexe2x80x9d as used herein refers to a line which substantially constitutes a character regardless of whether or not the line contains a character. The term xe2x80x9cnull linexe2x80x9d as used herein refers to a line meeting conditions that no character is inputted and the slewing operation is conducted in a line and that the subsequent lines contains no determined character. If the tape printing apparatus can indicate whether the display line is a substantial line or a null line as a line attribute, the user can easily know, even when the display line is changed from a substantial line to a null line, whether or not the null line is successfully accepted by the tape printing apparatus.
However, the displaying manners of the line number indicators are limited to three manners: blinking display state (that is, display and non-display of outline numeral appear in a repeated manner), light-on display state (that is, outline numeral is displayed), and light-off display state, so that four or more attributes or the like cannot be displayed. Due to this limitation, in the conventional printing apparatus, it is impossible to causes the line number indicators 3-1 to 3-4 to indicate the attribute indicative of whether the display line is the substantial line or a null line.
As a constitution in which four or more displaying manners are realized, there can be mentioned a constitution in which an area for displaying a line number is provided in the character display area 2. Actually, a tape printing apparatus having this configuration exists.
However, when the constitution is adopted in which the line number displaying area is provided in the character display area 2, the display apparatus become large by the area corresponding to the line number displaying area. Therefore, this constitution cannot be applied to low-price tape printing apparatuses requiring a smaller size and a lower cost. To the contrary, when a constitution in which the line number displaying area is provided in the character display area 2, a problem arises that the number of displayed input characters is reduced, so that the usability of the tape printing apparatus is lowered.
The same problem occurs in seal making apparatuses in which the number of characters to be engraved on the seal face is limited.
The present invention is accomplished in view of the above-described problems.
It is therefore an object of the present invention is to provide a character display apparatus capable of displaying characters, such as numerals, can be displayed in any one of various displaying manners.
Another object of the present invention is to provide a character input apparatus capable of informing the user of various kinds of information as to each line of the character input string while keeping the display device neither complicated nor large-sized.
In order to achieve the above objects, a first aspect of the present invention provides a character display apparatus including (1) character display means having at least a character segment formed in the shape of a character, and a background segment which is provided in such a manner as to surround the character segment and constitutes a background of an outline character; and (2) display control means for performing on-off control of the character segment and the background segment.
Further, a second aspect of the present invention provides a character input apparatus including: (1) display means having a character display area in which a number of lines displayed in a display area is smaller than the maximum input allowable line number and the dot display method is employed, and a plurality of line number indicators each of which corresponds to each of the lines of the input allowable maximum line number and is adapted to display the line attribute of each line, such as an input state and a display state; and (2) display control means for controlling the display of the display means, wherein (3) each of the line number indicators comprises a numeral segment in the shape of a numeral indicative of a line number, and a background segment which is provided in such a manner as to surround the numeral segment and constitutes a background of an outline numeral; and (4) the display control means performs on-off control of the numeral segment and the background segment in accordance with an input state or display state of each line.